Pianoforte



UNITED sTATEs PATENT oEEroE.

EDWIN BROWN, OF BOSTON, MASSACHUSETTS.

PIANOFORTE.

Specification of Letters PatentNo. 2,934, dated January 27, 1843.l

To aZZ 'whom t may concern Be it known `that I, EDWIN BROWN, of Boston,in the county of Suii'olk and State of Massachusetts, pianofortemanufacturer, and a citizen of the United States, have in vented anImprovement in the Action of Pianofortes, of which the following is atrue, full, and exact description.

The object of my improvement is to obtain a more certain and perfectrepetition of any note, to obtain a repetitionl by a slighter, andlighter touch of the key, and a more jready, easy and prompt action, andto prevent, what is termed the blocking of the hammer.

`The action of a pianoforte consistsy of the mechanical apparatuswhereby the stroke of the hammer is given upon the wire and the soundproduced. A distinct action belongs to each key' of the instrument.

In the annexed drawings a, a, a, a, Figure l represents alsection of theplatform or base,` by which the' action is in part supported. The keyZJ, Z), is a Vlever workingupon its pivot at c, and putting the actioninmotion when pressed down by the v finger. The jack, cZ, cZ, is framedinto the key. Zhen the key is pressed downby the finger it acts throughthe `jack (Z, CZ, and its front CZ2, (Z2, upon the under hammer e, e, e,e. The front jack (Z2, is a lever turning upon its pivot at The underhammer acts upon the upper hammer g, g, g, g, and causes it to strikethe wire Zt, Z1., and produce the sound.

The action as above described is in common use.- The method of applyingthe spring z', i, as described below, belongsv to the improvement madeby me. It has a coil' at the left-hand part as seen in this drawing,forthe purpose of increasing its elasticity, and being free and notsupported and not attached to' any part of the frame at that part. Theblock j, is fixed to the jack and moves with it and may be considered aspart of the jack. One extremity of the' spring is attached to the top ofthe block, and thus in effect attached and fixed to the jack, andaccordingly when the jack is moved by the motion ofthe key the m0- tionacts upon the spring, which rises and drops with the jack. The blockj,is also one of my improvements. It is attached to the jack by a screwinserted through a verticalslot in the block, as is shown in Fig. 5,

and accordingly on turning the screw so as to loosen the block, theblockmay be moved up or down and adjusted and fixed in any position desiredby again screwing it down. The spring may be attached directly to thekey, or the jack, and this regulating block thus dispensed with, butfrom experiment of the different modes of lixing the spring I think thatof fixing it to the regulating block decidedly preferable. Aback view ofthis regulating block j, is given in Fig. 7 The regulating block may beattached to some fixture or vstandard upon, or projection standing upfrom the key, and the spring attached to the block thus adjusted, andthis will be the same in effect asl attaching it to the jack. l/Vhent-he regulating block or someequivalent contrivance for slackening andstifl'ening the spring and regulating its tension is not used, then thespring may be attached directly to the jack, or in front of or behindthecjack to the key or to some xture, standard, or projection from thejack or the key, or the spring may be secu-red at or through its coil,by a pivot to a block suitable for thev purpose, and such block bescrewed or attached to the under side of the under hammer rail or framem, m', and when the key is pressed do-wn the end of one branch of thespring be made to tra-verse in the grooved block 7c, as described below,and the end of the other branch to traverse in like manner in a grooveinthe upper end of the regulating block y'. This will as has beenascertained by experiment, produce the same effect as attaching thespring to the jack. The grooves must of course be in the direction ofthe branch of the spring the end of which traverses in themrespectively. It is evident-ly necessary that the spring should in thiscase, play freely at the pivot. Attached to the under hammer e, e, e, e,is the block 7c, which may be considered to be a part of that hammer;this isalso a part of my improvement. On the under side of this blockZc, is a beveled groove'extending quite across the block in thedirectionof the key, that is, in the direction from front to rea-r of thepianoforte, which groove is lined or faced with soft leather. Fig. 8represents a transverse section of this block 7c, exhibiting the form ofthe groove., The upper extremity of the spring z', z', lies in the angleof the groove, so that when by the motion of the key the is raised orlowered by the motion of the key, slides to and fro in the angle of thisgroove. The tendency of the spring when the jack is raised, obviously isto raise the lower hammer e, e, e, c, as its upper extremity bearsgently upward against the lever of that hammer, but it is not the peeculiar function of this spring to raise the hammer and give the strokeupon the wire. this being done mainly by the action of the front of thejack (Z2, upon the lower hammer e, c, e, e, and this upon the upperhammer g, g, g, g in the manner heretofore in common use.

The function of the spring is to cooperate in raising the hammer, and tocheck and lighten their descent, whereby the performer is enabled togive a delicate repetition of the stroke at the elevation of thefingered part of the key, at half of its full sweep or vibration.Another function of the spring is to return the key to its proper'resting position, and accordingly by the use of the spring, the use of aweight for this purpose is dispensed with, or a lighter weight used.rlhe spring which I have used in my pianos is of number' l0 steel wire,but the size and material of the wire may be varied and the object ofthe impro-vement be still successfully effected. The tension and forceof the spring is regulated by adjusting the block y', at a higher orlower position on the jack; The wire or rod. Z, Z, is also as applied byme, a part of my improvement. It is inserted into, and projects from,and is fixed to the jack and accordingly moves with the jack. ltterminates at the top in the form of a rightangled hook or elbow, asrepresented in Fig. 7. The return part or arm projects hori- Zontallyacross the lever of the lower hammer e, e, e, e, so that when the key ofthe piano is at rest, this horizontal arm or projection is in slightcont-act with the soft leather coating of the upper surface of thatlever, and accordingly when the key of the instrument is inA its restingposition, the lower hammer must be in its resting position upon the topof the front jack CZZ. As the jack is raised this hook Z, Z, is raisedfrom off the lever of the lower hammer. The use of this hook is tosecure the lower hammer to be in its proper resting position, when thekey of the instrument comes to its resting position. rllhe side of thelever of the lower hammer, c, c, e, e, is cut away so as to make spacefor this hook Z, Z, to play backward and forward when the action of theinstrument is put in motion, see Fig. G. This also is part of myimproven'ient.

rllhe changing of the form ef the frame, a section of which isrepresented in drawings m, m, n, n, Fig. l, is also a part of myimprovement, the common form of this part of the frame beingquadrilateral with opposite sides about parallel to each other. Theupper part of the rail heretofore in use corresponds in position withthe upper surface of mine, marked m, m, in Fig. l, but the common rail,is much thicker vertically, the .lower part being removed in myimprovement so as to make room for the spring. rlhe posterior part n, n,is attached to the other m, m, for the purpose of strengthening it andrendering it a firm and su'tlicient support for that part of the actionwhich is connected with that part of the frame, the part a, n, isunscrewed and taken olf in order to come at and regulate the spring.

Another part of my impro-vement is the wire 0, 0, Fig. l, and theapparat-us p, Q, fr' and t. The wire is screwed or otherwise attachedand xed to the front ack (Z2. The use of it is to cooperate in throwingolf the top of the front jack (Z2, from the under hammer, anddisengaging it from that hammer when the stroke is given. Suchdisengagement is requisite in playing upon the instrument, and isintended always to take place in instruments in common use. This part ofmy improvement is intended to secure it more certainly.

ln the same drawing Fig. l, s, represents a section of the front railwhich extends from one end to the other of the instrument, on which apart of the action is supported, Z, is a beveled projection inward, thatis, backward from that front rail, and may be of the same piece of wood,or a piece glued, or otherwise attached and ixed to that front rail, theripper surface of which projecting ledge is beveling, or oblique to theback of the rail, making the angle with it shown by the position of theblock r, which is attac-hed and fixed to such ledge. A screw g, worksthrough the block r, to the lower end of which screw is attached andfixed a cushion 7), faced with soft leather, which cushion is regulatedby the screw, and may be proj ected downward or drawn upward by turningthe screw. The curved end of the wire o, 0, as the jack CZ, tZ, israised, comes in slight contact with the face of the cushion 72, andthus cooperates te throw forward the top of the front jack Z2 anddisengage it from the under hammer.

l claim as my invention, and ask a patent forl. The use of the springz', z', attached by means of a regulating block to the jack or the key,or, attached directly to the jack or key, or to a fixture or standardupon, or projection from, the jack or key, or to the rail or frame asabove described, and for the purpose above described.

2. The block constructed and adapted, as above described, for Ythepurpose above described.

3. The grooved block c, constructed and llt) described, and as shown inthe annexed 15 drawings, Fig. l, m, m, n, n.

7. The Wire 0, 0, and apparatus p, g', r, and t, constructed and adaptedas above described and for the purpose above described.

In Witness Whereo:l I hereto set my hand 20 this nineteenth day ofJanuary in the year of our Lord one thousand eight hundred andforty-two.

EDVIN BROWN.

Vitnesses RICH. RoBINs, WILLARD PHILLIPS.

